W.M. Fawley, E. Allaria, and E. Ferrari,
   "Real-World Considerations for Crossed-Polarized Undulator Radiation Conversion",
   in Proc. 37th International Free Electron Laser Conference, Daejeon, Republic of Korea, August 2015, paper TUP053, pp. 486-489,
    ISBN: 978-3-95450-134-2,
    doi:10.18429/JACoW-FEL2015-TUP053,
    http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/tup053.pdf, 2015.